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 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package java.awt.image;

import java.awt.color.ColorSpace;
import java.awt.geom.Rectangle2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.geom.Point2D;

import sun.awt.image.ImagingLib;

/**
 * This class implements a lookup operation from the source
 * to the destination.  The LookupTable object may contain a single array
 * or multiple arrays, subject to the restrictions below.
 * <p>
 * For Rasters, the lookup operates on bands.  The number of
 * lookup arrays may be one, in which case the same array is
 * applied to all bands, or it must equal the number of Source
 * Raster bands.
 * <p>
 * For BufferedImages, the lookup operates on color and alpha components.
 * The number of lookup arrays may be one, in which case the
 * same array is applied to all color (but not alpha) components.
 * Otherwise, the number of lookup arrays may
 * equal the number of Source color components, in which case no
 * lookup of the alpha component (if present) is performed.
 * If neither of these cases apply, the number of lookup arrays
 * must equal the number of Source color components plus alpha components,
 * in which case lookup is performed for all color and alpha components.
 * This allows non-uniform rescaling of multi-band BufferedImages.
 * <p>
 * BufferedImage sources with premultiplied alpha data are treated in the same
 * manner as non-premultiplied images for purposes of the lookup.  That is,
 * the lookup is done per band on the raw data of the BufferedImage source
 * without regard to whether the data is premultiplied.  If a color conversion
 * is required to the destination ColorModel, the premultiplied state of
 * both source and destination will be taken into account for this step.
 * <p>
 * Images with an IndexColorModel cannot be used.
 * <p>
 * If a RenderingHints object is specified in the constructor, the
 * color rendering hint and the dithering hint may be used when color
 * conversion is required.
 * <p>
 * This class allows the Source to be the same as the Destination.
 *
 * @see LookupTable
 * @see java.awt.RenderingHints#KEY_COLOR_RENDERING
 * @see java.awt.RenderingHints#KEY_DITHERING
 */

public class LookupOp implements BufferedImageOp, RasterOp {
    private LookupTable ltable;
    private int numComponents;
    RenderingHints hints;

    /**
     * Constructs a <code>LookupOp</code> object given the lookup
     * table and a <code>RenderingHints</code> object, which might
     * be <code>null</code>.
     *
     * @param lookup the specified <code>LookupTable</code>
     * @param hints  the specified <code>RenderingHints</code>,
     *               or <code>null</code>
     */
    public LookupOp(LookupTable lookup, RenderingHints hints) {
        this.ltable = lookup;
        this.hints = hints;
        numComponents = ltable.getNumComponents();
    }

    /**
     * Returns the <code>LookupTable</code>.
     *
     * @return the <code>LookupTable</code> of this
     * <code>LookupOp</code>.
     */
    public final LookupTable getTable() {
        return ltable;
    }

    /**
     * Performs a lookup operation on a <code>BufferedImage</code>.
     * If the color model in the source image is not the same as that
     * in the destination image, the pixels will be converted
     * in the destination.  If the destination image is <code>null</code>,
     * a <code>BufferedImage</code> will be created with an appropriate
     * <code>ColorModel</code>.  An <code>IllegalArgumentException</code>
     * might be thrown if the number of arrays in the
     * <code>LookupTable</code> does not meet the restrictions
     * stated in the class comment above, or if the source image
     * has an <code>IndexColorModel</code>.
     *
     * @param src the <code>BufferedImage</code> to be filtered
     * @param dst the <code>BufferedImage</code> in which to
     *            store the results of the filter operation
     * @return the filtered <code>BufferedImage</code>.
     * @throws IllegalArgumentException if the number of arrays in the
     *                                  <code>LookupTable</code> does not meet the restrictions
     *                                  described in the class comments, or if the source image
     *                                  has an <code>IndexColorModel</code>.
     */
    public final BufferedImage filter(BufferedImage src, BufferedImage dst) {
        ColorModel srcCM = src.getColorModel();
        int numBands = srcCM.getNumColorComponents();
        ColorModel dstCM;
        if (srcCM instanceof IndexColorModel) {
            throw new
                    IllegalArgumentException("LookupOp cannot be " +
                    "performed on an indexed image");
        }
        int numComponents = ltable.getNumComponents();
        if (numComponents != 1 &&
                numComponents != srcCM.getNumComponents() &&
                numComponents != srcCM.getNumColorComponents()) {
            throw new IllegalArgumentException("Number of arrays in the " +
                    " lookup table (" +
                    numComponents +
                    " is not compatible with the " +
                    " src image: " + src);
        }


        boolean needToConvert = false;

        int width = src.getWidth();
        int height = src.getHeight();

        if (dst == null) {
            dst = createCompatibleDestImage(src, null);
            dstCM = srcCM;
        } else {
            if (width != dst.getWidth()) {
                throw new
                        IllegalArgumentException("Src width (" + width +
                        ") not equal to dst width (" +
                        dst.getWidth() + ")");
            }
            if (height != dst.getHeight()) {
                throw new
                        IllegalArgumentException("Src height (" + height +
                        ") not equal to dst height (" +
                        dst.getHeight() + ")");
            }

            dstCM = dst.getColorModel();
            if (srcCM.getColorSpace().getType() !=
                    dstCM.getColorSpace().getType()) {
                needToConvert = true;
                dst = createCompatibleDestImage(src, null);
            }

        }

        BufferedImage origDst = dst;

        if (ImagingLib.filter(this, src, dst) == null) {
            // Do it the slow way
            WritableRaster srcRaster = src.getRaster();
            WritableRaster dstRaster = dst.getRaster();

            if (srcCM.hasAlpha()) {
                if (numBands - 1 == numComponents || numComponents == 1) {
                    int minx = srcRaster.getMinX();
                    int miny = srcRaster.getMinY();
                    int[] bands = new int[numBands - 1];
                    for (int i = 0; i < numBands - 1; i++) {
                        bands[i] = i;
                    }
                    srcRaster =
                            srcRaster.createWritableChild(minx, miny,
                                    srcRaster.getWidth(),
                                    srcRaster.getHeight(),
                                    minx, miny,
                                    bands);
                }
            }
            if (dstCM.hasAlpha()) {
                int dstNumBands = dstRaster.getNumBands();
                if (dstNumBands - 1 == numComponents || numComponents == 1) {
                    int minx = dstRaster.getMinX();
                    int miny = dstRaster.getMinY();
                    int[] bands = new int[numBands - 1];
                    for (int i = 0; i < numBands - 1; i++) {
                        bands[i] = i;
                    }
                    dstRaster =
                            dstRaster.createWritableChild(minx, miny,
                                    dstRaster.getWidth(),
                                    dstRaster.getHeight(),
                                    minx, miny,
                                    bands);
                }
            }

            filter(srcRaster, dstRaster);
        }

        if (needToConvert) {
            // ColorModels are not the same
            ColorConvertOp ccop = new ColorConvertOp(hints);
            ccop.filter(dst, origDst);
        }

        return origDst;
    }

    /**
     * Performs a lookup operation on a <code>Raster</code>.
     * If the destination <code>Raster</code> is <code>null</code>,
     * a new <code>Raster</code> will be created.
     * The <code>IllegalArgumentException</code> might be thrown
     * if the source <code>Raster</code> and the destination
     * <code>Raster</code> do not have the same
     * number of bands or if the number of arrays in the
     * <code>LookupTable</code> does not meet the
     * restrictions stated in the class comment above.
     *
     * @param src the source <code>Raster</code> to filter
     * @param dst the destination <code>WritableRaster</code> for the
     *            filtered <code>src</code>
     * @return the filtered <code>WritableRaster</code>.
     * @throws IllegalArgumentException if the source and destinations
     *                                  rasters do not have the same number of bands, or the
     *                                  number of arrays in the <code>LookupTable</code> does
     *                                  not meet the restrictions described in the class comments.
     */
    public final WritableRaster filter(Raster src, WritableRaster dst) {
        int numBands = src.getNumBands();
        int dstLength = dst.getNumBands();
        int height = src.getHeight();
        int width = src.getWidth();
        int srcPix[] = new int[numBands];

        // Create a new destination Raster, if needed

        if (dst == null) {
            dst = createCompatibleDestRaster(src);
        } else if (height != dst.getHeight() || width != dst.getWidth()) {
            throw new
                    IllegalArgumentException("Width or height of Rasters do not " +
                    "match");
        }
        dstLength = dst.getNumBands();

        if (numBands != dstLength) {
            throw new
                    IllegalArgumentException("Number of channels in the src ("
                    + numBands +
                    ") does not match number of channels"
                    + " in the destination ("
                    + dstLength + ")");
        }
        int numComponents = ltable.getNumComponents();
        if (numComponents != 1 && numComponents != src.getNumBands()) {
            throw new IllegalArgumentException("Number of arrays in the " +
                    " lookup table (" +
                    numComponents +
                    " is not compatible with the " +
                    " src Raster: " + src);
        }


        if (ImagingLib.filter(this, src, dst) != null) {
            return dst;
        }

        // Optimize for cases we know about
        if (ltable instanceof ByteLookupTable) {
            byteFilter((ByteLookupTable) ltable, src, dst,
                    width, height, numBands);
        } else if (ltable instanceof ShortLookupTable) {
            shortFilter((ShortLookupTable) ltable, src, dst, width,
                    height, numBands);
        } else {
            // Not one we recognize so do it slowly
            int sminX = src.getMinX();
            int sY = src.getMinY();
            int dminX = dst.getMinX();
            int dY = dst.getMinY();
            for (int y = 0; y < height; y++, sY++, dY++) {
                int sX = sminX;
                int dX = dminX;
                for (int x = 0; x < width; x++, sX++, dX++) {
                    // Find data for all bands at this x,y position
                    src.getPixel(sX, sY, srcPix);

                    // Lookup the data for all bands at this x,y position
                    ltable.lookupPixel(srcPix, srcPix);

                    // Put it back for all bands
                    dst.setPixel(dX, dY, srcPix);
                }
            }
        }

        return dst;
    }

    /**
     * Returns the bounding box of the filtered destination image.  Since
     * this is not a geometric operation, the bounding box does not
     * change.
     *
     * @param src the <code>BufferedImage</code> to be filtered
     * @return the bounds of the filtered definition image.
     */
    public final Rectangle2D getBounds2D(BufferedImage src) {
        return getBounds2D(src.getRaster());
    }

    /**
     * Returns the bounding box of the filtered destination Raster.  Since
     * this is not a geometric operation, the bounding box does not
     * change.
     *
     * @param src the <code>Raster</code> to be filtered
     * @return the bounds of the filtered definition <code>Raster</code>.
     */
    public final Rectangle2D getBounds2D(Raster src) {
        return src.getBounds();

    }

    /**
     * Creates a zeroed destination image with the correct size and number of
     * bands.  If destCM is <code>null</code>, an appropriate
     * <code>ColorModel</code> will be used.
     *
     * @param src    Source image for the filter operation.
     * @param destCM the destination's <code>ColorModel</code>, which
     *               can be <code>null</code>.
     * @return a filtered destination <code>BufferedImage</code>.
     */
    public BufferedImage createCompatibleDestImage(BufferedImage src,
                                                   ColorModel destCM) {
        BufferedImage image;
        int w = src.getWidth();
        int h = src.getHeight();
        int transferType = DataBuffer.TYPE_BYTE;
        if (destCM == null) {
            ColorModel cm = src.getColorModel();
            Raster raster = src.getRaster();
            if (cm instanceof ComponentColorModel) {
                DataBuffer db = raster.getDataBuffer();
                boolean hasAlpha = cm.hasAlpha();
                boolean isPre = cm.isAlphaPremultiplied();
                int trans = cm.getTransparency();
                int[] nbits = null;
                if (ltable instanceof ByteLookupTable) {
                    if (db.getDataType() == db.TYPE_USHORT) {
                        // Dst raster should be of type byte
                        if (hasAlpha) {
                            nbits = new int[2];
                            if (trans == cm.BITMASK) {
                                nbits[1] = 1;
                            } else {
                                nbits[1] = 8;
                            }
                        } else {
                            nbits = new int[1];
                        }
                        nbits[0] = 8;
                    }
                    // For byte, no need to change the cm
                } else if (ltable instanceof ShortLookupTable) {
                    transferType = DataBuffer.TYPE_USHORT;
                    if (db.getDataType() == db.TYPE_BYTE) {
                        if (hasAlpha) {
                            nbits = new int[2];
                            if (trans == cm.BITMASK) {
                                nbits[1] = 1;
                            } else {
                                nbits[1] = 16;
                            }
                        } else {
                            nbits = new int[1];
                        }
                        nbits[0] = 16;
                    }
                }
                if (nbits != null) {
                    cm = new ComponentColorModel(cm.getColorSpace(),
                            nbits, hasAlpha, isPre,
                            trans, transferType);
                }
            }
            image = new BufferedImage(cm,
                    cm.createCompatibleWritableRaster(w, h),
                    cm.isAlphaPremultiplied(),
                    null);
        } else {
            image = new BufferedImage(destCM,
                    destCM.createCompatibleWritableRaster(w,
                            h),
                    destCM.isAlphaPremultiplied(),
                    null);
        }

        return image;
    }

    /**
     * Creates a zeroed-destination <code>Raster</code> with the
     * correct size and number of bands, given this source.
     *
     * @param src the <code>Raster</code> to be transformed
     * @return the zeroed-destination <code>Raster</code>.
     */
    public WritableRaster createCompatibleDestRaster(Raster src) {
        return src.createCompatibleWritableRaster();
    }

    /**
     * Returns the location of the destination point given a
     * point in the source.  If <code>dstPt</code> is not
     * <code>null</code>, it will be used to hold the return value.
     * Since this is not a geometric operation, the <code>srcPt</code>
     * will equal the <code>dstPt</code>.
     *
     * @param srcPt a <code>Point2D</code> that represents a point
     *              in the source image
     * @param dstPt a <code>Point2D</code>that represents the location
     *              in the destination
     * @return the <code>Point2D</code> in the destination that
     * corresponds to the specified point in the source.
     */
    public final Point2D getPoint2D(Point2D srcPt, Point2D dstPt) {
        if (dstPt == null) {
            dstPt = new Point2D.Float();
        }
        dstPt.setLocation(srcPt.getX(), srcPt.getY());

        return dstPt;
    }

    /**
     * Returns the rendering hints for this op.
     *
     * @return the <code>RenderingHints</code> object associated
     * with this op.
     */
    public final RenderingHints getRenderingHints() {
        return hints;
    }

    private final void byteFilter(ByteLookupTable lookup, Raster src,
                                  WritableRaster dst,
                                  int width, int height, int numBands) {
        int[] srcPix = null;

        // Find the ref to the table and the offset
        byte[][] table = lookup.getTable();
        int offset = lookup.getOffset();
        int tidx;
        int step = 1;

        // Check if it is one lookup applied to all bands
        if (table.length == 1) {
            step = 0;
        }

        int x;
        int y;
        int band;
        int len = table[0].length;

        // Loop through the data
        for (y = 0; y < height; y++) {
            tidx = 0;
            for (band = 0; band < numBands; band++, tidx += step) {
                // Find data for this band, scanline
                srcPix = src.getSamples(0, y, width, 1, band, srcPix);

                for (x = 0; x < width; x++) {
                    int index = srcPix[x] - offset;
                    if (index < 0 || index > len) {
                        throw new
                                IllegalArgumentException("index (" + index +
                                "(out of range: " +
                                " srcPix[" + x +
                                "]=" + srcPix[x] +
                                " offset=" + offset);
                    }
                    // Do the lookup
                    srcPix[x] = table[tidx][index];
                }
                // Put it back
                dst.setSamples(0, y, width, 1, band, srcPix);
            }
        }
    }

    private final void shortFilter(ShortLookupTable lookup, Raster src,
                                   WritableRaster dst,
                                   int width, int height, int numBands) {
        int band;
        int[] srcPix = null;

        // Find the ref to the table and the offset
        short[][] table = lookup.getTable();
        int offset = lookup.getOffset();
        int tidx;
        int step = 1;

        // Check if it is one lookup applied to all bands
        if (table.length == 1) {
            step = 0;
        }

        int x = 0;
        int y = 0;
        int index;
        int maxShort = (1 << 16) - 1;
        // Loop through the data
        for (y = 0; y < height; y++) {
            tidx = 0;
            for (band = 0; band < numBands; band++, tidx += step) {
                // Find data for this band, scanline
                srcPix = src.getSamples(0, y, width, 1, band, srcPix);

                for (x = 0; x < width; x++) {
                    index = srcPix[x] - offset;
                    if (index < 0 || index > maxShort) {
                        throw new
                                IllegalArgumentException("index out of range " +
                                index + " x is " + x +
                                "srcPix[x]=" + srcPix[x]
                                + " offset=" + offset);
                    }
                    // Do the lookup
                    srcPix[x] = table[tidx][index];
                }
                // Put it back
                dst.setSamples(0, y, width, 1, band, srcPix);
            }
        }
    }
}
